The overall objective of this "Research Center of Excellence in Pediatric Nephrology and Urology" is to provide a coordinated, interdisciplinary and multi-institutional approach to studies seeking to elucidate mechanisms regulating renal and urological function during fetal and postnatal development. The main theme of this Research Center is "Ontogeny of Neurochemical Control of Renal and Urological Function during Normal and Pathological Conditions." The approaches that will be used to achieve this general objective are board, ranging from studies on molecular and cellular mechanisms to integrate studies of physiological and neurophysiological phenomena. Projects 1 and 2 involve the role of the sympathetic nervous system and adrenergic system in modulating body fluid homeostasis during early development. More specifically, Project 1 will investigate the ontogeny of mechanisms regulating renal sympathetic nerve activity during fetal and postnatal life. Project 2 will test the hypothesis that different peptide hormones influence renal adrenergic receptors and post-receptor mechanisms during maturation. Project 3 will provide new insight into the molecular processes regulating renin biosynthesis, trafficking and release by the developing kidney. Project 4 will use molecular biology and integrative physiology approaches to test the hypothesis that ANP mediates sodium homeostasis early during development and plays a role in the adaptation of the developing kidney to unilateral ureteral obstruction. The Research Center will be supported by two core facilities: Administration and Education. The close thematic relation of the research projects and the history of productive collaboration between investigators represent a unique opportunity to expand our knowledge and to obtain new and important information on mechanisms regulating the development of the kidney and urinary tract.